1. Field of the Invention
This invention relates to a polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial. The polymeric composition is a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from quaternary ammonium compounds, gentian violet compounds, substituted or unsubstituted phenols, biguanide compounds, iodine compounds, and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups on the polymer.
2. Description of the Related Art
Many medical procedures involve the placement of medical devices, such as catheters, endotracheal tubes, prostheses, grafts, sutures, dressings and implants, in the human body. Infection is a common complication associated with the use of such medical devices. Accordingly, many research efforts have concentrated on finding means to prevent infection associated with these implantable medical devices.
One solution to this infection problem has been the use of medical device coatings having antimicrobial agents. An “antimicrobial” agent is an agent that has antiviral, antibacterial, and/or antifungal properties. (Antiviral means capable of killing or suppressing the replication of viruses. Antibacterial means bacteriostatic or bactericidal where bactericidal means the killing of microorganisms and bacteriostatic means inhibiting the growth of microorganisms. Antifungal means capable of killing or suppressing replication of fungi.)
It has been particularly desirable to use a coating for implantable medical devices that is bacteriostatic, i.e., inhibits bacterial growth, such that the device can be implanted for longer periods without compromising the subject through a secondary bacterial infection. Various compounds have been incorporated into polymeric materials or polymeric coatings to provide for an implantable medical device that is bacteriostatic. For example, U.S. Pat. No. 6,224,579 B1 discloses polymeric medical articles comprising triclosan and/or other chlorinated phenols and silver containing compounds. U.S. Pat. Nos. 5,707,366, 4,999,210 and 4,675,347 disclose medical articles having a chlorhexidine coating. U.S. Pat. No. 5,709,672 discloses polymeric medical articles comprising gentian violet and/or silver containing compounds. U.S. Pat. No. 5,328,698 discloses polymeric medical articles comprising quaternary ammonium compounds. U.S. Pat. No. 5,069,907 discloses medical articles comprising triclosan. U.S. Pat. No. 6,162,487 discloses polymeric medical articles comprising chlorhexidine, methylisothiazolone, terpineol, thymol, chloroxylenol, and/or cetylpyridinium chloride. U.S. Pat. Nos. 4,323,557, 4,310,509 and 4,128,633 disclose medical articles having iodine compound coatings. U.S. Pat. No. 4,605,564 discloses polymeric medical articles comprising chlorinated phenols.
Even though various medical device coatings having antimicrobial agents are known, there is still a need for an improved antimicrobial polymer coating that may be easily applied to a substrate to provide an article which has excellent antimicrobial properties and which retains its antimicrobial properties in a permanent and non-leachable fashion when in contact with bodily fluids for prolonged periods. In addition, it would be beneficial if this coating could be combined with an anti-thrombogenic coating to prevent both clotting and bacterial infection.